Abe Rosenthal, the long-serving former executive editor of the New York Times, used to have a recurring nightmare: that he would wake up someday to find that the Times had ceased to exist. It is a commentary on the paper’s much-diminished prestige that many now dream of such a day.

William McGowan doesn’t. While critical of what he considers the paper’s decline, he writes as an admirer of the Times and its place in American history. In his view, the Times once stood as a model of fair-minded, responsible journalism and an important civic and political institution in its own right. The problem, as he points out in his book, Gray Lady Down, is that the Times has remained a hugely influential organization even as it has abandoned its once lofty journalistic standards.

It was not always thus. Recalling the paper’s glory days, McGowan pays tribute to the late Rosenthal’s editorship. Though a political liberal, Rosenthal didn’t want the paper to become a sounding board for left-wing politics. He checked the paper’s drift to the left, particularly in its Washington bureau, by insisting that reporters conduct objective reporting and avoid potential conflicts of interest. Rosenthal memorably summed up his editorial policy: “I don’t care if my reporters are fucking elephants, as long as they aren’t covering the circus.” It’s a testament to Rosenthal’s dispassionate approach to news reporting that in 1972, William F. Buckley’s National Review—hardly a reflexive ally of the Times’s progressive politics—called for other media to emulate the paper’s standards.

If it’s hard to imagine a similar endorsement today, it’s because the Times, in McGowan’s view, has become a very different, and much less worthy, enterprise. McGowan attributes the paper’s decline to two main causes. The first is its embrace of so-called lifestyle journalism in the 1970s. Designed to give the staid “Gray Lady” a trendy makeover and lure a younger demographic, the focus on soft news failed to increase readership. It did, however, open the door for the left-wing politics that Rosenthal had resisted and which would gradually shape the paper’s cultural coverage. A case in point is the Times Book Review, a once-diverse forum for intellectual debate that now often shuns conservative titles, even when they top the paper’s own extended bestseller list.

The second factor in the Times’s decline was the ascension of Arthur Sulzberger, Jr. to the perch of publisher in 1992. Having come of age in the sixties counterculture, Sulzberger moved to shift the paper’s focus from its historical commitment of reporting the news “without fear or favor” to the more activist promise to “enhance society.” In particular, Sulzberger wanted the paper to promote “diversity” and to move beyond what he disparaged as the “predominantly white, straight, male version of events.” As the author of Coloring the News, a critical look at the politically correct mania for “diversity” and its damaging effect on the news media, McGowan writes as an authority on the Times’s transformation. The change was most obvious in the paper’s increasingly strident editorial pages, but the news content, which began taking its cues from editorial, suffered as well. Times veterans groused that the paper risked compromising its news coverage with a newly ideological agenda, but Sulzberger dismissed such concerns, declaring that he was “setting a moral standard.”

The paper’s diversity obsession culminated in the calamitous tenure of Howell Raines. Admired by Sulzberger for his uncompromising and outspoken leftism, Raines became executive editor in 2001 and presided over a series of journalistic disasters that badly tarnished the Times’s editorial brand. The biggest of these, which would cost Raines his job, involved a young black reporter named Jayson Blair. Recruited through a minority internship, Blair was promoted over the objections of his editors as part of the paper’s diversity drive. A national correspondent by the time he was 27, Blair wasn’t ready for the role. During his seven months on the job, Blair fabricated details in at least 38 of 73 stories, conning editors by lifting details from photos and other news stories and appending datelines of locations from which he had not reported.

The fallout from Blair’s fraud in May 2003 ended not only Raines’s Times career, but also that of Gerald Boyd, the paper’s first black managing editor. Sulzberger called the scandal the “low point in the paper’s 150-year history.” The Blair affair was a damning indictment of the paper’s “diversity” agenda, but it was not an isolated incident. McGowan shows how the Times’s ideological hobby horses make it uniquely susceptible to such hoaxes. A more recent example was the paper’s scandalously prejudicial early coverage of the 2006 Duke University “rape” case, in which a black stripper accused three white Duke lacrosse players of raping her at a team party. Because the Timescovered the story through the prism of race, sex, and class, much of its initial reporting echoed the baseless charges of radical professors like Duke’s Houston Baker, who claimed that the lacrosse players were “white, violent, drunken men . . . veritably given license to rape.” As evidence mounted that the players’ accuser had made up her story, the Times corrected the record, but not before it had done grave damage to the reputations of three innocent young men.

On the cultural side, the Times’s weakness for diversity cant has made it an easy target for literary con artists. In 2004, the paper was taken in by “J. T. LeRoy,” the supposedly transgendered cult novelist whose background as a “young truck-stop prostitute who had escaped rural West Virginia for the dismal life of a homeless San Francisco drug addict,” as described by the Times’ Warren St. John, had impressed credulous reporters and reviewers at the paper. It later emerged that none of these biographical details was true—not least that “he” was actually a (non-transgendered) “she,” Laura Albert. That revelation must have been especially embarrassing for St. John, who didn’t discover it even after dining with “LeRoy” in broad daylight.

McGowan mocks such PC-inspired faux pas, but his most compelling chapters chronicle a more serious failure: the paper’s biased, politicized, and often damaging reporting on national security and the domestic threat of Islamic terrorism. Though it will come as no surprise to regular readers, McGowan shows that the Times has consistently failed to explore the religious motivations of Islamic jihadists. When Army major Nidal Hasan killed 13 soldiers and wounded 30 at Fort Hood in November 2009, the Times’s editorialists lamented that “no one can begin to imagine what could possibly have motivated this latest appalling outrage.” In reality, Hasan, a self-styled “Soldier of Allah,” had a long track record of Islamic extremism that left little doubt about his motivations. Yet one wouldn’t know it from the paper’s coverage, which failed to explore the religious angle and to investigate how Hasan was able to rise through the army’s ranks despite countless warnings about the danger he posed to his fellow soldiers. McGowan also considers a number of other cases where the paper’s apparent political sensitivities have prevented it from doing hard reporting about Islamic extremism in America. Plainly, not all the news is fit to print.

Where Islamic extremism inspires timidity at the Times, national-security measures aimed at keeping the country safe from terrorism bring out the paper’s adversarial worst. In December 2005, the Times on its front page broke the story of the National Security Agency’s classified program monitoring the phone and email communications of terrorist suspects in the United States. The paper not only published the story over the appeals of the Bush administration, which warned that it could compromise terrorist surveillance, but it also suggested that the program had limited security value. Not until the release of a classified report by five inspectors general in 2009 did the paper get around to acknowledging that the NSA surveillance program had in fact been a useful early detection tool for counterterrorist agencies. The paper’s coverage of the PATRIOT Act and the SWIFT banking surveillance program, which monitored the transactions of suspected terrorists, was similarly one-sided and antagonistic. The skeptical reader might muse here that such coverage would seem par for the course for a news organization that published the Pentagon Papers on the Vietnam War in 1971. But as McGowan reminds us, the Times agonized over that earlier decision and agreed to publish the documents only after it determined that current military secrets would not be exposed. No such restraint governs the paper’s national-security coverage today.

Fed up with the Times’s political agenda and its ideological crusades, many on the right have sworn off the paper. McGowan believes that this is a mistake. While less influential than it once was, the paper still shapes much of the coverage that other media follow, and it remains a major influence on the country’s political and intellectual elite. The day the New York Times is no longer around may not be the nightmare that Abe Rosenthal imagined, but we ignore the paper at our peril.